org.springframework.beans.NotWritablePropertyException: Invalid property 'userDao' of bean class [co

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userService' defined in class path resource [applicationContext.xml]: Error setting property values; nested exception is org.springframework.beans.NotWritablePropertyException:
Invalid property 'userDao' of bean class [com.ywr.shopping.service.impl.UserServiceImpl]: Bean property 'userDao' is not writable or has an invalid setter method. Did you mean 'userDAO'?

Caused by: org.springframework.beans.NotWritablePropertyException: Invalid property 'userDao' of bean class [com.ywr.shopping.service.impl.UserServiceImpl]: Bean property 'userDao' is not writable or has an invalid setter method. Did you mean 'userDAO'?
at org.springframework.beans.BeanWrapperImpl.setPropertyValue(BeanWrapperImpl.java:793)
at org.springframework.beans.BeanWrapperImpl.setPropertyValue(BeanWrapperImpl.java:645)
at org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:78)
at org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:59)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1127)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:862)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:423)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:249)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:155)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:246)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:160)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:291)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:352)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:122)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:76)
at org.springframework.test.AbstractSingleSpringContextTests.loadContextLocations(AbstractSingleSpringContextTests.java:138)
at org.springframework.test.AbstractSingleSpringContextTests.loadContext(AbstractSingleSpringContextTests.java:125)
at org.springframework.test.AbstractSpringContextTests.getContext(AbstractSpringContextTests.java:104)
at org.springframework.test.AbstractSingleSpringContextTests.setUp(AbstractSingleSpringContextTests.java:75)
at junit.framework.TestCase.runBare(TestCase.java:132)
at org.springframework.test.ConditionalTestCase.runBare(ConditionalTestCase.java:69)
at junit.framework.TestResult$1.protect(TestResult.java:110)
at junit.framework.TestResult.runProtected(TestResult.java:128)

at junit.framework.TestResult.run(TestResult.java:113)
at junit.framework.TestCase.run(TestCase.java:124)
at junit.framework.TestSuite.runTest(TestSuite.java:232)
at junit.framework.TestSuite.run(TestSuite.java:227)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:79)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:46)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

出现异常的原因是在application-xxx.xml中property name的错误

如果Service这样定义实现方法：

那么application-xxx.xml应该定义为：

定义bean id="userService"，必须property name="userDAO"，因为Service方法中是setter注入bean的。